Means for maintaining synchronous rotation of dynamo-electric machines.



No. 650,677. Patented May 29, I900. H. GEISENHUNER & C. D. KNIGHT. MEANS FOR MAINTAINING SYNCI'IRDNOUS ROTATION UF DYNAMO ELECTRIC MACHINES.

(Application filed Nov. 16. 1899.)

(No Model.)

' wltnesses. Jnventorrs ,Q, Henr GeisenIt'mer (I char'Is DKnight.

Nrran STATES I PATE T OFFICE.

HENRY CEIsENHGNEE AND CHAELEs D. KNIGHT, or s HENECTADY, NEW YORK, AssIeNoEs TO THE GENERAL ELECTRIC COMPANY,

OF NEW YORK.

MEANS FOR MAINTAINING SYNCHRONOUS ROTATION OF DYNAMO-ELECIRIC MACHINES.

SPECIFICATION forming part of Letters Patent No. 650,877, dated May 29, 1900.

Application filed November 16, 1899- Serial No. 737,174, (No model.)

To all whom it may concern.-

Be it known that we, HENRY GEISENHdNER and CHARLES D. KNIGHT, citizens of the United States, residing at Schenectady, in the county of Schenectady and State of New York, have invented certain new and useful Improvements in Means for Maintaining Synchronous Rotation of Dynamo-Electric Machines, (Case No. 1,354,)011 which the followin g is a specification.

In a certain pending application for Letters Patent filed by Edwin WV. Rice, J r., and Ernst J. Berg on the28th day of August, 1899, serially numbered 728,651, there is disclosed what is sometimes known as the copper bridge, a device which finds its greatest application in preventing the hunting of dynamo-electric machines and particularly rotary converters. It is not necessary here to explain in detail the whole theory of operation of these bridges; but it should be sufficient to say that they operate by opposing the tendency to variation in the cross-magnetizing flux of the machine to which they are applied. It has been found that hunting of rotary converters cannot take place without some variation in this cross-magnetizing action and that when the variation is suppressed or strongly opposed the hunting is decreased to a marked extent and with proper design is commercially eliminated. The bridges disclosed in the above-mentioned application consist of castings of copper or other highly-conductive material arranged to span the interpolar spaces of the field-magnets, each forming a low-resistance circuit around one of said spaces, and to extend slightly under the polar tips, since the cross-magnetizing flux necessarily seeks the polar tips, owing to their high magnetic permeability.

Our invention relates to improvements in the mechanical construction of the copper bridges above mentioned; and it consists in certain arrangements whereby the construction, application, and removal of the bridges are materially simplified.

The exact nature of our invention will be fully set forth hereinafter, and its scope will be definitely pointed out in the claims annexed to this specification.

In the drawings hereto attached, Figure l is a general view of a dynamo-electric machine to which our improved bridges have been attached. Fig. 2 is a plan view of one of the bridges, and Fig. 3 is an end elevation of a bridge with the adjacent pole-tips.

The dynamo-electric machine is shown in Fig. 1 in outline to a suflicient extent to show how our improvements are applied.

1 is the field-magnet'frame. pole pieces which carry the magnetizing-coils 3 3, and 4 is the armature, which may be of any well-known type. r r

- The construction of the bridges 5 will be clearly understood by reference to Figs. 2 and 3, from which it will be seen that they are each formed with two parallel sides 6 G, connected by curved end pieces 7 7. The curved pieces are preferably integral with the sides, and the whole bridge is formed of one cast ing. The end pieces are tapped with holes near their centers, and a bolt 8 passes through these holes. This bolt is capable of being tightened by a nut 9.

The peculiar shape of the side pieces, which is well shown in Fig. 3, is such as to enable the bridge as a whole to be slipped in place on the machine by passing it in from the end, provided always that the distance between two side pieces is properly adjusted with ref; erence to the distance between the pole-pieces of the machine. When the bridges are thus slipped into position, the nut 9 is tightened,

and the curved arms 7 are bent by what is really a toggle-joint action in such a way as to spread farther apart the side pieces 6 6. and to hold the whole bridge tightly in place.

In some bridges constructed in accordance. with our present invention we have formed each of the side pieces 7 7 of pivoted links in such a way as to produce toggle-joints of the usual well=known form; but We find in prac tice that it is preferable to use the curved end pieces shown in the drawings and to form them andthe whole bridge of some metal which is to a certain extent yielding and flexible or elastic. We find that either copper or any of the soft alloys of copper will answer the purpose.

It will be seen that our improved construc 2 2 are the by Letters Patent of the United States, is-

1. As a means of improving the operationof a dynamo-electric machine, a bridge of conducting material provided with means for adjusting its width.

2. As a means of improving the operation of a dynamo-electric machine, a bridge of conducting material formed with sides and provided with means for varying the distance between the sides.

3. A conducting-bridge formed with parallel sides, with a toggle device for adjusting the distance between the said sides.

4.-. A bridge formed of a single piece of conducting material having sides and curved end pieces, with means for bending the curved end pieces for varying the distance between the two sides.

5. As an article of manufacture, a bridge of conducting material having two parallel grooved sides connected by curved endpieces, with a tightening device arranged to bend the two curved sides.

6. As an article of manufacture a conducting-bridge formed with two parallel curved sides connected by two curved end pieces, and a bolt passing through the end pieces for varying the distance between the sides.

7. The combination with a dynamo-electric machine, of an adjustable conducting-bridge spanning the interpolar space.

In witness whereof we have hereunto set our hands this 14th day of November, 1899.

HENRY emsnnnonns. CHARLES D. KNIGHT.

\Vit-nesses:

BENJAMIN 1- HULL, MABEL E. JAooBsoN. 

